Product details of 7pcs 2.35/3.17mm Brass Collet Mini Drill Chucks For Electric Motor Shaft Drill Features:*1. This 0.5-3mm twist drill chuck set is made of copper with excellent workmanship. *2. It is suitable for 0.5-3.0MM drill bit.*3. For small drills, after connecting with the motor, drill holes for the PCB circuit board with special micro drills.*4. It can be used for drilling holes such as ABS board, wood, sheet aluminum, cardboard, etc.Description:*1. Adapter Drill: 0.5mm-3.0mm*2. Material: Copper*3. Color: Gold*4. Copper Drill Folder Size: 2.35mm/ 3.17mmPackage includes:1x Small Wrench1x Copper Drill Folder1x 0.5mm Drill Collet1x 1.0mm Drill Collet1x 1.5mm Drill Collet1x 2.5mm Drill Collet1x 3.0mm Drill Collet Features: *1. This 0.5-3mm twist drill chuck set is made of copper with excellent workmanship. *2. It is suitable for 0.5-3.0MM drill bit. *3. For small drills, after connecting with the motor, drill holes for the PCB circuit board with special micro drills. *4. It can be used for drilling holes such as ABS board, wood, sheet aluminum, cardboard, etc. Description: *1. Adapter Drill: 0.5mm-3.0mm *2. Material: Copper *3. Color: Gold *4. Copper Drill Folder Size: 2.35mm/ 3.17mm Package includes: 1x Small Wrench 1x Copper Drill Folder 1x 0.5mm Drill Collet 1x 1.0mm Drill Collet 1x 1.5mm Drill Collet 1x 2.5mm Drill Collet 1x 3.0mm Drill Collet Features:*1. This 0.5-3mm twist drill chuck set is made of copper with excellent workmanship. *2. It is suitable for 0.5-3.0MM drill bit.*3. For small drills, after connecting with the motor, drill holes for the PCB circuit board with special micro drills.*4. It can be used for drilling holes such as ABS board, wood, sheet aluminum, cardboard, etc.Description:*1. Adapter Drill: 0.5mm-3.0mm*2. Material: Copper*3. Color: Gold*4. Copper Drill Folder Size: 2.35mm/ 3.17mmPackage includes:1x Small Wrench1x Copper Drill Folder1x 0.5mm Drill Collet1x 1.0mm Drill Collet1x 1.5mm Drill Collet1x 2.5mm Drill Collet1x 3.0mm Drill Collet